Safety guard for a rotatable member

A system for preventing entanglement by contact with a rotating rod assembly for driving a downhole pump, the system comprising:

• a drive head having
• a housing from which the rotating rod assembly extends, the rod assembly comprising a rotating rod and a rod clamp for operatively connecting the rotating rod to a main driven shaft extending upwardly from the housing and being rotatable therewith;
• and
• a tubular guard positioned concentrically about the driven member, forming an annulus therebetween, the guard having a moment of inertia;
• and
• an anti-friction interface within the annulus for enabling differential rotation between the guard and the driven member,
• when, during normal operation, the safety guard is unrestrained, the guard is free to co-rotate with the driven member;
• and
• when restrained by contact therewith, the moment of inertia enables rotation of the guard to cease rotation while the driven member continues to rotate therein.